This invention relates to a felt construction for use in a papermaking machine, and more particularly to a felt construction which functions to control rewetting of the paper web upon exit of the web from a press nip of the papermaking machine.
Rewetting of a paper web as the paper web exits the press nip of the papermaking machine is a recognized problem in the papermaking industry. Various patents address this problem, including U.S. Pat. No. 3,214,327 Wicker et al; U.S. Pat. No. 3,214,331 Wicker; U.S. Pat. No. 3,556,940 Cronin; U.S. Pat. No. 4,162,190 Ashworth; U.S. Pat. No. 4,199,401 Liu et al; U.S. Pat. No. 4,988,409 Nyberg; and U.S. Pat. No. 5,182,164 Ecklund et al; as well as U.S. Pat. No. 5,372,876 issued to the inventors herein.
It is an object of the present invention to provide an improved papermaking felt capable of efficiently and effectively removing water from the paper web at the press nip and efficiently and effectively impeding backflow of water through the felt as pressure imposed on the felt by the press nip is released.
It is another object of the invention to provide an improved papermaking felt which is relatively simple in construction yet which performs in a highly satisfactory manner to facilitate removing water from the web and to impede rewetting of the web.
It is a further object to provide an improved papermaking felt having at least one layer comprising non-circular filaments therein, the non-circular filaments facilitating achievement of the desired removal of water from the paper web.
It is a more specific object to provide an improved papermaking felt having at least one layer comprising at least 10% by weight non-circular filaments therein, the non-circular filaments facilitating achievement of the desired removal of water from the paper web.
It is a yet further object to provide an improved papermaking felt having at least one layer comprising at least 10% tri-lobed filaments therein, the tri-lobed filaments facilitating achievement of the desired removal of water from the paper web.